Electronic controls and monitoring systems are advantageously included with work machines and complex tools. Such systems typically include input circuitry for conditioning signals received from sensors located about the machine. The sensors advantageously provide signals indicative of the level of sensed parameters and which are important to the operation of the electronic control or monitoring system. Similarly the input circuitry cooperates with the sensors in providing signals indicative of the sensed parameter value.
Each sensor type requires different circuitry, for example, resistive type sensors require a pull-up resistor to produce the signal indicating the level of the sensed parameter; whereas, frequency type or pulse width modulated sensors may be delivered directly to edge capturing hardware. Since each sensor type or family of sensors requires a different type of input circuitry, dedicated inputs were required for each type of sensor to be used in connection with the particular control or monitoring system. With there being a predefined subset of inputs associated with each sensor type or family of types, flexibility is necessarily limited. This lack of flexibility in prior art systems led to the use of separate controls for each application or the inefficient use of inputs. To reduce manufacturing costs, warehousing space, and the like, it is advantageous to be able to use a single design in connection with a number of different machine types or versions.
The present invention is directed to overcoming one or more of the problems set forth above.